Described herein is a flash remapping (FR) layer in a storage operating system for utilizing flash memory as a secondary permanent storage device in a storage system. The FR layer collects particular information (specified by collection parameters) of received access requests for data stored on primary storage devices of the storage system. Based on the collected information and a predetermined access pattern (specified by pattern parameters), the FR layer selects data sets on the primary storage devices to be transferred permanently to flash memory, whereby subsequent access requests to the selected data sets are redirected to flash memory. New parameters may be received by the FR layer (from a user or program) to dynamically reconfigure the functions of the FR layer. The FR layer may be implemented in the operating system without requiring other code of the storage operating system to be modified.